This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. This project is designed to test the hypothesis that developmental mechanisms underlie the etiology and poor outcomes of pediatric major depressive disorder (MDD). Through an integrative approach, we propose to use a 2x2 study design examine development within cortico-limbic networks in younger and older adolescents, with and without MDD. We propose to obtain neuroimaging data including stuctural, diffusion tensor, resting functional, and spectropscopic imaging. Since we have proposed to limit our depressed subjects to those who are treatment-naive, we request 12 months to collect this pilot data.